Reprogramming Filamentous fd Viruses to Capture Copper Ions.

Area of Science:

• Biotechnology
• Materials Science
• Environmental Science

Background:

• Filamentous bacteriophages (phages) are increasingly explored as scaffolds for novel biomaterials.
• The peptide HGFANVA, identified for its Cu(II) specificity, was genetically engineered onto fd phages.

Purpose of the Study:

• To investigate the Cu(II) binding and mineralization capabilities of engineered fd phages displaying truncated HGFANVA variants.
• To explore the potential of these genetically modified phages for bioremediation and circular economy applications.

Main Methods:

• Display of C-terminal truncated HGFANVA variants on wild-type fd phages.
• Treatment of engineered and wild-type phages with Cu(II) solutions.
• Characterization using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), and Energy Dispersive X-ray Spectroscopy (EDX).
• Metal ion binding assessed via Enzyme-Linked Immunosorbent Assay (ELISA).

Main Results:

• Engineered phages formed aggregated, bundle-like assemblies with significant mineral deposition upon Cu(II) exposure.
• Shorter peptide variants (A, NVA, ANVA) at lower concentrations formed nanowire-like assemblies.
• Wild-type phages showed no mineral formation, and Cu peaks were only detected on engineered viruses.
• Engineered viruses demonstrated Cu(II) binding and mineralization, even without the His (H) unit.

Conclusions:

• Genetically reprogrammed phages can effectively bind Cu(II) and form mineralized structures.
• These virus-based materials show promise for bioremediation and contributing to a circular economy.